The American geologistGrove Karl Gilbert surveyed this area in 1875 and 1876, and published his findings in 1879 as a monograph, The Geology of the Henry Mountains. The term laccolith was first applied as laccolite by Gilbert after his study of intrusions of diorite in the Henry Mountains.[4] Mount Ellsworth's name appeared on an 1875 map, but the origin is a mystery.[5] One possibility is Elmer E. Ellsworth, (1837–1861).[6] Gilbert did name nearby Mount Holmes, four miles to the northeast.
Climate
Spring and fall are the most favorable seasons to visit Mount Ellsworth. According to the Köppen climate classification system, it is located in a Cold semi-arid climate zone, which is defined by the coldest month having an average mean temperature below 32 °F (0 °C), and at least 50% of the total annual precipitation being received during the spring and summer. This desert climate receives less than 10 inches (250 millimeters) of annual rainfall, and snowfall is generally light during the winter.